diff --git a/.travis.yml b/.travis.yml
index 4c12c17e..242767ec 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,7 +8,7 @@ deploy:
   provider: releases
   api_key: ${GH_TOKEN}
   file_glob: true
-  file: "${TRAVIS_BUILD_DIR}/java-sdk/build/libs/*.jar"
+  file: "*/build/libs/*.jar"
   skip_cleanup: true
   on:
     tags: true
@@ -16,5 +16,8 @@ deploy:
 before_install:
   - cd java-sdk
 
+before_deploy:
+  - pwd
+
 after_deploy:
   - ./gradlew bintrayUpload
diff --git a/commons/biovotion/biovotion_vsm_battery_state.avsc b/commons/biovotion/biovotion_vsm_battery_state.avsc
index ea3bcbc4..85cbdab9 100644
--- a/commons/biovotion/biovotion_vsm_battery_state.avsc
+++ b/commons/biovotion/biovotion_vsm_battery_state.avsc
@@ -7,8 +7,8 @@
     {"name": "time", "type": "double", "doc": "device timestamp in UTC (s)"},
     {"name": "timeReceived", "type": "double", "doc": "device receiver timestamp in UTC (s)"},
     {"name": "batteryLevel", "type": "float", "doc": "battery level (0-1)"},
-    {"name": "batteryChargeRate", "type": "float", "doc": "battery charge rate (0-1)"},
+    {"name": "batteryChargeRate", "type": "float", "doc": "battery charge rate, level change per hour (0-1)"},
     {"name": "batteryVoltage", "type": "float", "doc": "battery voltage (V)"},
-    {"name": "batteryStatus", "type": "float", "doc": "battery status"}
+    {"name": "batteryStatus", "type": "float", "doc": "battery status; 0:not charging, not on charger; 2:not charging, on charger; 3:charging, on charger"}
   ]
 }
diff --git a/commons/biovotion/biovotion_vsm_led_current.avsc b/commons/biovotion/biovotion_vsm_led_current.avsc
new file mode 100644
index 00000000..77bdc169
--- /dev/null
+++ b/commons/biovotion/biovotion_vsm_led_current.avsc
@@ -0,0 +1,14 @@
+{
+  "namespace": "org.radarcns.biovotion",
+  "type": "record",
+  "name": "BiovotionVSMLedCurrent",
+  "doc": "Applied current for red, green and ir leds.",
+  "fields": [
+    {"name": "time", "type": "double", "doc": "device timestamp in UTC (s)"},
+    {"name": "timeReceived", "type": "double", "doc": "device receiver timestamp in UTC (s)"},
+    {"name": "red", "type": "float", "doc": "current for red LED (mA)"},
+    {"name": "green", "type": "float", "doc": "current for green LED (mA)"},
+    {"name": "ir", "type": "float", "doc": "current for IR LED (mA)"},
+    {"name": "offset", "type": "float", "doc": "current offset (mA)"}
+  ]
+}
diff --git a/commons/biovotion/biovotion_vsm_ppg_raw.avsc b/commons/biovotion/biovotion_vsm_ppg_raw.avsc
new file mode 100644
index 00000000..e34f9dd6
--- /dev/null
+++ b/commons/biovotion/biovotion_vsm_ppg_raw.avsc
@@ -0,0 +1,14 @@
+{
+  "namespace": "org.radarcns.biovotion",
+  "type": "record",
+  "name": "BiovotionVSMPhotoRaw",
+  "doc": "Raw 14bit Photodiode ADC data for red, green, IR and dark portions (PPG raw data).",
+  "fields": [
+    {"name": "time", "type": "double", "doc": "device timestamp in UTC (s)"},
+    {"name": "timeReceived", "type": "double", "doc": "device receiver timestamp in UTC (s)"},
+    {"name": "red", "type": "float", "doc": "raw red light ADC response (normalized)"},
+    {"name": "green", "type": "float", "doc": "raw green light ADC response (normalized)"},
+    {"name": "ir", "type": "float", "doc": "raw IR light ADC response (normalized)"},
+    {"name": "dark", "type": "float", "doc": "raw dark light ADC response (normalized)"}
+  ]
+}
diff --git a/commons/biovotion/biovotion_vsm_temperature.avsc b/commons/biovotion/biovotion_vsm_temperature.avsc
index b6bdf5b8..f794f78d 100644
--- a/commons/biovotion/biovotion_vsm_temperature.avsc
+++ b/commons/biovotion/biovotion_vsm_temperature.avsc
@@ -2,12 +2,12 @@
   "namespace": "org.radarcns.biovotion",
   "type": "record",
   "name": "BiovotionVSMTemperature",
-  "doc": "Data from temperature sensor expressed degrees on the Celsius (°C) scale.",
+  "doc": "Data from temperature sensor expressed in degrees on the Celsius (°C) scale.",
   "fields": [
     {"name": "time", "type": "double", "doc": "device timestamp in UTC (s)"},
     {"name": "timeReceived", "type": "double", "doc": "device receiver timestamp in UTC (s)"},
-    {"name": "temperature", "type": "float", "doc": "local temperature (°C)"},
-    {"name": "temperatureObject", "type": "float", "doc": "object temperature (°C)"},
+    {"name": "temperature", "type": "float", "doc": "skin temperature (°C)"},
+    {"name": "temperatureLocal", "type": "float", "doc": "device (board) temperature (°C)"},
     {"name": "temperatureBarometer", "type": "float", "doc": "barometer temperature (°C)"}
   ]
 }
diff --git a/commons/key/windowed_key.avsc b/commons/key/windowed_key.avsc
index 315f8a93..a6ccdbc1 100644
--- a/commons/key/windowed_key.avsc
+++ b/commons/key/windowed_key.avsc
@@ -3,8 +3,8 @@
   "name": "WindowedKey",
   "doc": "Windowed key in the RADAR-CNS project",
   "fields": [
-    {"name": "userID", "type": "string"},
-    {"name": "sourceID", "type": "string"},
+    {"name": "userId", "type": "string"},
+    {"name": "sourceId", "type": "string"},
     {"name": "start", "type": "long"},
     {"name": "end", "type": "long"}
   ]
diff --git a/commons/phone/phone_call.avsc b/commons/phone/phone_call.avsc
index c9e3fc60..4997dddf 100644
--- a/commons/phone/phone_call.avsc
+++ b/commons/phone/phone_call.avsc
@@ -8,6 +8,9 @@
     {"name": "timeReceived", "type": "double", "doc": "device receiver timestamp in UTC (s)"},
     {"name": "duration", "type": "float", "doc": "duration of the call (s)", "default": "NaN"},
     {"name": "target", "type": ["null", "bytes"], "doc": "HMAC SHA-256 one-way source/target of the call. This hash of a given phone number will be the same unless the app is reinstalled. If the number is unknown or anonymous, this contains null.", "default": null},
-    {"name": "type", "type": {"name": "PhoneCallType", "type": "enum", "symbols": ["INCOMING", "OUTGOING", "MISSED", "VOICEMAIL", "UNKNOWN"]}, "doc": "direction of phone call", "default": "UNKNOWN"}
+    {"name": "type", "type": {"name": "PhoneCallType", "type": "enum", "symbols": ["INCOMING", "OUTGOING", "MISSED", "VOICEMAIL", "UNKNOWN"]}, "doc": "direction of phone call", "default": "UNKNOWN"},
+    {"name": "targetIsContact", "type": ["null","boolean"], "doc": "call to/from a known contact, null if unknown", "default": null},
+    {"name": "targetIsNonNumeric", "type": "boolean", "doc": "sms sender ID is replaced by text, e.g. a company name", "default": false},
+    {"name": "targetLength", "type": "int", "doc": "length of the target phone number, -1 if not collected.", "default": -1}
   ]
-}
\ No newline at end of file
+}
diff --git a/commons/phone/phone_gyroscope.avsc b/commons/phone/phone_gyroscope.avsc
new file mode 100644
index 00000000..df5a1c33
--- /dev/null
+++ b/commons/phone/phone_gyroscope.avsc
@@ -0,0 +1,13 @@
+{
+  "namespace": "org.radarcns.phone",
+  "type": "record",
+  "name": "PhoneGyroscope",
+  "doc": "Data from the 3-axis gyroscope.",
+  "fields": [
+    {"name": "time", "type": "double", "doc": "device timestamp in UTC (s)"},
+    {"name": "timeReceived", "type": "double", "doc": "device receiver timestamp in UTC (s)"},
+    {"name": "x", "type": "float", "doc": "gyration in the x-axis (rad/s)"},
+    {"name": "y", "type": "float", "doc": "gyration in the y-axis (rad/s)"},
+    {"name": "z", "type": "float", "doc": "gyration in the z-axis (rad/s)"}
+  ]
+}
diff --git a/commons/phone/phone_magnetic_field.avsc b/commons/phone/phone_magnetic_field.avsc
new file mode 100644
index 00000000..7a562d64
--- /dev/null
+++ b/commons/phone/phone_magnetic_field.avsc
@@ -0,0 +1,13 @@
+{
+  "namespace": "org.radarcns.phone",
+  "type": "record",
+  "name": "PhoneMagneticField",
+  "doc": "Data from the 3-axis magnetometer.",
+  "fields": [
+    {"name": "time", "type": "double", "doc": "device timestamp in UTC (s)"},
+    {"name": "timeReceived", "type": "double", "doc": "device receiver timestamp in UTC (s)"},
+    {"name": "x", "type": "float", "doc": "magnetic field in the x-axis (μT)"},
+    {"name": "y", "type": "float", "doc": "magnetic field in the y-axis (μT)"},
+    {"name": "z", "type": "float", "doc": "magnetic field in the z-axis (μT)"}
+  ]
+}
diff --git a/commons/phone/phone_sms.avsc b/commons/phone/phone_sms.avsc
index ac5b7fb6..46bb17c1 100644
--- a/commons/phone/phone_sms.avsc
+++ b/commons/phone/phone_sms.avsc
@@ -8,6 +8,9 @@
     {"name": "timeReceived", "type": "double", "doc": "device receiver timestamp in UTC (s)"},
     {"name": "target", "type": ["null", "bytes"], "doc": "HMAC SHA-256 one-way source/target of the SMS. This hash of a given phone number will be the same unless the app is reinstalled. If the number is unknown or anonymous, this contains null.", "default": null},
     {"name": "type", "type": {"name": "PhoneSmsType", "type": "enum", "symbols": ["INCOMING", "OUTGOING", "OTHER", "UNKNOWN"]}, "doc": "direction of the SMS", "default": "UNKNOWN"},
-    {"name": "length", "type": "int", "doc": "number of characters in the message (-1 if unknown)", "default": -1}
+    {"name": "length", "type": ["null","int"], "doc": "number of characters in the message (null if unknown)", "default": null},
+    {"name": "targetIsContact", "type": ["null","boolean"], "doc": "sms sender is a known contact, null if unknown", "default": null},
+    {"name": "targetIsNonNumeric", "type": "boolean", "doc": "sms sender ID is replaced by text, e.g. a company name", "default": false},
+    {"name": "targetLength", "type": "int", "doc": "length of the target phone number, -1 if not collected.", "default": -1}
   ]
-}
\ No newline at end of file
+}
diff --git a/commons/phone/phone_sms_unread.avsc b/commons/phone/phone_sms_unread.avsc
new file mode 100644
index 00000000..8927dc5a
--- /dev/null
+++ b/commons/phone/phone_sms_unread.avsc
@@ -0,0 +1,11 @@
+{
+  "namespace": "org.radarcns.phone",
+  "type": "record",
+  "name": "PhoneSmsUnread",
+  "doc": "Number of SMS messages in the inbox that have an unread status.",
+  "fields": [
+    {"name": "time", "type": "double", "doc": "device timestamp in UTC (s)"},
+    {"name": "timeReceived", "type": "double", "doc": "device receiver timestamp in UTC (s)"},
+    {"name": "unreadSMS", "type": "int", "doc": "number of unread SMS messages currently in the inbox"}
+  ]
+}
diff --git a/commons/phone/phone_step_count.avsc b/commons/phone/phone_step_count.avsc
new file mode 100644
index 00000000..1936582f
--- /dev/null
+++ b/commons/phone/phone_step_count.avsc
@@ -0,0 +1,11 @@
+{
+  "namespace": "org.radarcns.phone",
+  "type": "record",
+  "name": "PhoneStepCount",
+  "doc": "Data from the step counter.",
+  "fields": [
+    {"name": "time", "type": "double", "doc": "device timestamp in UTC (s)"},
+    {"name": "timeReceived", "type": "double", "doc": "device receiver timestamp in UTC (s)"},
+    {"name": "steps", "type": "int", "doc": "number of steps taken between this and the previous record"}
+  ]
+}
diff --git a/commons/phone/phone_usage_event.avsc b/commons/phone/phone_usage_event.avsc
new file mode 100644
index 00000000..ff9a9f34
--- /dev/null
+++ b/commons/phone/phone_usage_event.avsc
@@ -0,0 +1,16 @@
+{
+  "namespace": "org.radarcns.phone",
+  "type": "record",
+  "name": "PhoneUsageEvent",
+  "doc": "Event for closing or opening an app",
+  "fields": [
+    {"name": "time", "type": "double", "doc": "device timestamp in UTC (s)"},
+    {"name": "timeReceived", "type": "double", "doc": "device receiver timestamp in UTC (s)"},
+    {"name": "packageName", "type": "string", "doc": "package name of the launched app"},
+    {"name": "categoryName", "type": ["null", "string"], "doc": "app category as given by the play store, null if a category is not listed or unable to be fetched", "default": null},
+    {"name": "categoryNameFetchTime", "type": ["null", "double"], "doc": "timestamp in UTC when the category was attempted to fetch from the play store (s), null if not fetched", "default": null},
+    {"name": "eventType", "type":
+      {"name": "UsageEventType", "type": "enum", "symbols": ["FOREGROUND", "BACKGROUND", "CONFIG", "SHORTCUT", "INTERACTION", "NONE"]},
+      "doc": "whether the event brought app to foreground or background or neither", "default": "NONE"}
+  ]
+}
diff --git a/commons/phone/phone_user_interaction.avsc b/commons/phone/phone_user_interaction.avsc
index 29f8c10d..781f696b 100644
--- a/commons/phone/phone_user_interaction.avsc
+++ b/commons/phone/phone_user_interaction.avsc
@@ -6,6 +6,6 @@
   "fields": [
     {"name": "time", "type": "double", "doc": "device timestamp in UTC (s)"},
     {"name": "timeReceived", "type": "double", "doc": "device receiver timestamp in UTC (s)"},
-    {"name": "lockState", "type": {"name": "PhoneLockState", "type": "enum", "symbols": ["STANDBY", "UNLOCKED"]}, "doc": "what lock state the phone has"}
+    {"name": "interactionState", "type": {"name": "PhoneInteractionState", "type": "enum", "symbols": ["STANDBY", "UNLOCKED","SHUTDOWN","BOOTED"]}, "doc": "what interaction state the phone has"}
   ]
-}
\ No newline at end of file
+}
diff --git a/commons/questionnaire/questionnaire.avsc b/commons/questionnaire/questionnaire.avsc
new file mode 100644
index 00000000..6a36c15d
--- /dev/null
+++ b/commons/questionnaire/questionnaire.avsc
@@ -0,0 +1,28 @@
+{
+  "namespace": "org.radarcns.questionnaire",
+  "type": "record",
+  "name": "Questionnaire",
+  "doc": "General schema for questionnaire. Check the specification folder to see how the questionnaire has been defined. For each QuestionnaireType there is a JSON file reporting the questions set and possible answers if available",
+  "fields": [
+    { "name": "time", "type": "double", "doc": "timestamp in UTC (s) when the questionnaire is submitted to the subject" },
+    { "name": "timeCompleted", "type": "double", "doc": "timestamp in UTC (s) when subject marks the questionnaire as" },
+    { "name": "name", "type": {"name": "QuestionnaireType", "type": "enum", "symbols": ["PHQ8", "ESM", "UNKNOWN"]}, "doc": "Questionnaire names", "default": "UNKNOWN" },
+    { "name": "version", "type": "string", "doc": "It reports the questionnaire version stated in the JSON specification" },
+    { "name": "answers",
+      "type": {
+        "type": "array",
+        "items": {
+          "name": "Answer",
+          "type": "record",
+          "doc": "Questionnaire answer",
+            "fields": [
+              { "name": "value", "type": ["int", "string", "double"], "doc": "Subject answer" },
+              { "name": "startTime", "type": "double", "doc": "timestamp in UTC (s) when the question is shown" },
+              { "name": "endTime", "type": "double", "doc": "timestamp in UTC (s)  when the question is answered" }
+            ]
+         }
+      },
+      "doc": "Answers list. The answers order must follow the questions order"
+    }
+  ]
+}
diff --git a/java-sdk/build.gradle b/java-sdk/build.gradle
index 908b7536..bdd72bf2 100644
--- a/java-sdk/build.gradle
+++ b/java-sdk/build.gradle
@@ -15,7 +15,7 @@ subprojects {
     apply plugin: 'maven-publish'
 
     // Configuration
-    version = '0.1'
+    version = '0.2-alpha.1'
     group = 'org.radarcns'
     ext.githubRepoName = 'RADAR-CNS/RADAR-Schemas'
 
diff --git a/java-sdk/radar-schemas-restapi/build.gradle b/java-sdk/radar-schemas-restapi/build.gradle
index 3f8b9af2..5d300eca 100644
--- a/java-sdk/radar-schemas-restapi/build.gradle
+++ b/java-sdk/radar-schemas-restapi/build.gradle
@@ -5,12 +5,15 @@ ext.description = 'RADAR Schemas REST API SDK'
 // AVRO file manipulation                                                    //
 //---------------------------------------------------------------------------//
 task generateAvro(type: com.commercehub.gradle.plugin.avro.GenerateAvroJavaTask) {
+    source rootProject.fileTree('../commons') {
+        include 'questionnaire/questionnaire.avsc'
+        include 'application/application_server_status.avsc'
+    }
     source rootProject.fileTree('../restapi') {
         include '**/*.avsc'
     }
     outputDir avroOutputDir
 }
-
 compileJava.dependsOn generateAvro
 
 //---------------------------------------------------------------------------//
diff --git a/questionnaire/specification/DEMO_config.json b/questionnaire/specification/DEMO_config.json
new file mode 100644
index 00000000..958d0154
--- /dev/null
+++ b/questionnaire/specification/DEMO_config.json
@@ -0,0 +1,42 @@
+{
+  "name" : "DEMO",
+  "version": 1,
+  "estimatedCompletionTime" : 2,
+  "startText" : "Here you can test some all available input types.",
+  "endText" : "Thanks for giving it a try.",
+  "protocol" : {
+    "reminders" : {
+      "amount" : 15,
+      "repeat" : 1,
+      "unit" : "min"
+    },
+    "repeatProtocol" : {
+      "amount" : 2,
+      "unit" : "week"
+    },
+    "repeatQuestionnaire" : {
+      "unit" : "min",
+      "unitsFromZero" : [ 450, 600, 1890, 2004 ]
+    }
+  },
+  "questions" : [ {
+    "content" : "The slider as fine-grained input.",
+    "id" : "Test-0",
+    "lead" : "Some other input types.",
+    "range" : {
+      "max" : 100,
+      "min" : 0,
+      "step" : 5
+    },
+    "type" : "slider"
+  }, {
+    "content" : "The multiple values for a smaller range.",
+    "id" : "Test-2",
+    "lead" : "Some other input types.",
+    "range" : {
+      "max" : 7,
+      "min" : 1
+    },
+    "type" : "range"
+  } ]
+}
diff --git a/questionnaire/specification/PHQ8_config.json b/questionnaire/specification/PHQ8_config.json
new file mode 100644
index 00000000..80eed0fa
--- /dev/null
+++ b/questionnaire/specification/PHQ8_config.json
@@ -0,0 +1,149 @@
+{
+  "name" : "PHQ8",
+  "version": 1,
+  "estimatedCompletionTime" : 7,
+  "startText" : "This questionnaire is known as the PHQ8. Clinicians use it to assess current depression in patients. Thank you for taking part in this focus group.",
+  "endText" : "Thank you for participating today.",
+  "protocol" : {
+    "reminders" : {
+      "amount" : 15,
+      "repeat" : 2,
+      "unit" : "min"
+    },
+    "repeatProtocol" : {
+      "amount" : 1,
+      "unit" : "month"
+    },
+    "repeatQuestionnaire" : {
+      "unit" : "min",
+      "unitsFromZero" : [ 600 ]
+    }
+  },
+  "questions" : [ {
+    "content" : "Little interest or pleasure in doing things.",
+    "id" : "PHQ8-0",
+    "lead" : "Over the past two weeks, how often have you been bothered by any of the following problems?",
+    "responses" : [ {
+      "response" : "Not at all",
+      "score" : 0
+    }, {
+      "response" : "Several days",
+      "score" : 1
+    }, {
+      "response" : "More than half the days",
+      "score" : 2
+    }, {
+      "response" : "Nearly every day",
+      "score" : 3
+    } ],
+    "type" : "radio"
+  }, {
+    "content" : "Feeling down, depressed, or hopeless.",
+    "id" : "PHQ8-1",
+    "lead" : "Over the past two weeks, how often have you been bothered by any of the following problems?",
+    "responses" : [ {
+      "response" : "Not at all",
+      "score" : 0
+    }, {
+      "response" : "Several days",
+      "score" : 1
+    }, {
+      "response" : "More than half the days",
+      "score" : 2
+    }, {
+      "response" : "Nearly every day",
+      "score" : 3
+    } ],
+    "type" : "radio"
+  }, {
+    "content" : "Trouble falling asleep or staying asleep, or sleeping too much.",
+    "id" : "PHQ8-2",
+    "lead" : "Over the past two weeks, how often have you been bothered by any of the following problems?",
+    "responses" : [ {
+      "response" : "Not at all",
+      "score" : 0
+    }, {
+      "response" : "Several days",
+      "score" : 1
+    }, {
+      "response" : "More than half the days",
+      "score" : 2
+    }, {
+      "response" : "Nearly every day",
+      "score" : 3
+    } ],
+    "type" : "radio"
+  }, {
+    "content" : "Feeling tired or having little energy.",
+    "id" : "PHQ8-3",
+    "lead" : "Over the past two weeks, how often have you been bothered by any of the following problems?",
+    "responses" : [ {
+      "response" : "Not at all",
+      "score" : 0
+    }, {
+      "response" : "Several days",
+      "score" : 1
+    }, {
+      "response" : "More than half the days",
+      "score" : 2
+    }, {
+      "response" : "Nearly every day",
+      "score" : 3
+    } ],
+    "type" : "radio"
+  }, {
+    "content" : "Feeling bad about yourself – or that you are a failure or have let yourself or your family down.",
+    "id" : "PHQ8-4",
+    "lead" : "Over the past two weeks, how often have you been bothered by any of the following problems?",
+    "responses" : [ {
+      "response" : "Not at all",
+      "score" : 0
+    }, {
+      "response" : "Several days",
+      "score" : 1
+    }, {
+      "response" : "More than half the days",
+      "score" : 2
+    }, {
+      "response" : "Nearly every day",
+      "score" : 3
+    } ],
+    "type" : "radio"
+  }, {
+    "content" : "Trouble concentrating on things such as reading the newspaper of watching television.",
+    "id" : "PHQ8-5",
+    "lead" : "Over the past two weeks, how often have you been bothered by any of the following problems?",
+    "responses" : [ {
+      "response" : "Not at all",
+      "score" : 0
+    }, {
+      "response" : "Several days",
+      "score" : 1
+    }, {
+      "response" : "More than half the days",
+      "score" : 2
+    }, {
+      "response" : "Nearly every day",
+      "score" : 3
+    } ],
+    "type" : "radio"
+  }, {
+    "content" : "Moving or speaking so slowly that other people have noticed. Or the opposite – being so fidgety or restless that you have been moving around a lot more than usual.",
+    "id" : "PHQ8-6",
+    "lead" : "Over the past two weeks, how often have you been bothered by any of the following problems?",
+    "responses" : [ {
+      "response" : "Not at all",
+      "score" : 0
+    }, {
+      "response" : "Several days",
+      "score" : 1
+    }, {
+      "response" : "More than half the days",
+      "score" : 2
+    }, {
+      "response" : "Nearly every day",
+      "score" : 3
+    } ],
+    "type" : "radio"
+  } ]
+}
diff --git a/restapi/app/application.avsc b/restapi/app/application.avsc
index 29784b15..434536e6 100644
--- a/restapi/app/application.avsc
+++ b/restapi/app/application.avsc
@@ -4,9 +4,11 @@
   "name": "Application",
   "doc": "Smartphone application status",
   "fields": [
-    {"name": "ipAddress", "type": ["null", "string"], "doc": "Hardware identifier of client application", "default": null},
+    {"name": "ipAddress", "type": [
+      "null",
+      "string" ], "doc": "Hardware identifier of client application", "default": null},
     {"name": "uptime", "type": "double", "doc": "Time since last app start (s)"},
-    {"name": "serverStatus", "type": "ServerStatus", "doc": "server connection status", "default": "UNKNOWN"},
+    {"name": "serverStatus", "type": "org.radarcns.application.ServerStatus", "doc": "server connection status", "default": "UNKNOWN"},
     {"name": "recordsCached", "type": "int", "doc": "number of records currently being cached", "default": -1},
     {"name": "recordsSent", "type": "int", "doc": "number of records sent since application start"},
     {"name": "recordsUnsent", "type": "int", "doc": "number of unsent records", "default": -1}
diff --git a/restapi/app/server_status.avsc b/restapi/app/server_status.avsc
deleted file mode 100644
index 0a48935a..00000000
--- a/restapi/app/server_status.avsc
+++ /dev/null
@@ -1,7 +0,0 @@
-{
-  "namespace": "org.radarcns.avro.restapi.app",
-  "type": "enum",
-  "name": "ServerStatus",
-  "doc": "Set of device status",
-  "symbols": [ "CONNECTED" , "DISCONNECTED", "UNKNOWN" ]
-}
diff --git a/restapi/data/acceleration.avsc b/restapi/data/acceleration.avsc
new file mode 100644
index 00000000..6dc1fcf3
--- /dev/null
+++ b/restapi/data/acceleration.avsc
@@ -0,0 +1,11 @@
+{
+  "namespace": "org.radarcns.avro.restapi.data",
+  "type": "record",
+  "name": "Acceleration",
+  "doc": "Acceleration sample with gravitational constant g as unit.",
+  "fields": [
+    {"name": "x", "type": [ "double" , "org.radarcns.avro.restapi.data.Quartiles" ], "doc": "acceleration in the x-axis (g)"},
+    {"name": "y", "type": [ "double" , "org.radarcns.avro.restapi.data.Quartiles" ], "doc": "acceleration in the y-axis (g)"},
+    {"name": "z", "type": [ "double" , "org.radarcns.avro.restapi.data.Quartiles" ], "doc": "acceleration in the z-axis (g)"}
+  ]
+}
diff --git a/restapi/data/double_sample.avsc b/restapi/data/double_sample.avsc
new file mode 100644
index 00000000..b8f631e0
--- /dev/null
+++ b/restapi/data/double_sample.avsc
@@ -0,0 +1,9 @@
+{
+  "namespace": "org.radarcns.avro.restapi.data",
+  "type": "record",
+  "name": "DoubleSample",
+  "doc": "Generic sample represented by a double value. A specific schema is provided to represent quartile values.",
+  "fields": [
+    {"name": "value", "type": [ "double" , "org.radarcns.avro.restapi.data.Quartiles" ], "doc": "sample value"}
+  ]
+}
diff --git a/restapi/data/quartiles.avsc b/restapi/data/quartiles.avsc
new file mode 100644
index 00000000..5690710d
--- /dev/null
+++ b/restapi/data/quartiles.avsc
@@ -0,0 +1,11 @@
+{
+  "namespace": "org.radarcns.avro.restapi.data",
+  "type": "record",
+  "name": "Quartiles",
+  "doc": "List of quartiles",
+  "fields": [
+    {"name": "first", "type": "double", "doc": "the middle number between the smallest number and the median of the data set"},
+    {"name": "second", "type": "double", "doc": "the median of the data"},
+    {"name": "third", "type": "double", "doc": "the middle value between the median and the highest value of the data set"}
+  ]
+}
diff --git a/restapi/dataset/dataset.avsc b/restapi/dataset/dataset.avsc
index 9d59e87b..05ad8e83 100644
--- a/restapi/dataset/dataset.avsc
+++ b/restapi/dataset/dataset.avsc
@@ -2,9 +2,9 @@
   "namespace": "org.radarcns.avro.restapi.dataset",
   "type": "record",
   "name": "Dataset",
-  "doc": "A generic dataset containing aggregated data. Its body is divide in Header and Dataset: metadata and sensor data.",
+  "doc": "A generic collection of samples. Its body is divide in Header and Dataset: metadata and sensor data.",
   "fields": [
-    {"name": "header", "type": "org.radarcns.avro.restapi.header.Header" },
-    {"name": "dataset", "type": {"type": "array", "items": "Item" } }
+    {"name": "header", "type": "org.radarcns.avro.restapi.header.Header", "doc": "Information useful to contextualise the data set"},
+    {"name": "dataset", "type": {"type": "array", "items": "Item" }, "doc": "Collection of samples"}
   ]
 }
diff --git a/restapi/dataset/item.avsc b/restapi/dataset/item.avsc
index ab3a8fa2..667a6e6c 100644
--- a/restapi/dataset/item.avsc
+++ b/restapi/dataset/item.avsc
@@ -4,15 +4,11 @@
   "name": "Item",
   "doc": "Dataset item. It contains a value and its related time.",
   "fields": [
-    {"name": "value", "type": [
-      "org.radarcns.avro.restapi.sensor.HeartRate" ,
-      "org.radarcns.avro.restapi.sensor.Acceleration" ,
-      "org.radarcns.avro.restapi.sensor.Battery" ,
-      "org.radarcns.avro.restapi.sensor.BloodVolumePulse" ,
-      "org.radarcns.avro.restapi.sensor.ElectroDermalActivity" ,
-      "org.radarcns.avro.restapi.sensor.InterBeatInterval" ,
-      "org.radarcns.avro.restapi.sensor.Temperature"
-      ] } ,
-    {"name": "effectiveTimeFrame", "type": "org.radarcns.avro.restapi.header.EffectiveTimeFrame"}
+    {"name": "sample", "type": [
+      "org.radarcns.avro.restapi.data.DoubleSample" ,
+      "org.radarcns.avro.restapi.data.Acceleration",
+      "org.radarcns.questionnaire.Questionnaire"
+      ], "doc": "Sample value. For more details, check org.radarcns.avro.restapi.data.Acceleration, org.radarcns.avro.restapi.data.DoubleSample and org.radarcns.questionnaire.Questionnaire" } ,
+    {"name": "startDateTime", "type": "string", "doc": "Point in time (ISO8601) with UTC timezone. It represents the timestamp of the first sample contained inside the aggregated data."}
   ]
 }
diff --git a/restapi/dataset/quartiles.avsc b/restapi/dataset/quartiles.avsc
deleted file mode 100644
index 0e0e864e..00000000
--- a/restapi/dataset/quartiles.avsc
+++ /dev/null
@@ -1,11 +0,0 @@
-{
-  "namespace": "org.radarcns.avro.restapi.dataset",
-  "type": "record",
-  "name": "Quartiles",
-  "doc": "List of quartiles",
-  "fields": [
-    {"name": "first", "type": "double"},
-    {"name": "second", "type": "double"},
-    {"name": "third", "type": "double"}
-  ]
-}
diff --git a/restapi/header/descriptive_statistic.avsc b/restapi/header/descriptive_statistic.avsc
index b9f1f429..adf716c7 100644
--- a/restapi/header/descriptive_statistic.avsc
+++ b/restapi/header/descriptive_statistic.avsc
@@ -2,7 +2,7 @@
   "namespace": "org.radarcns.avro.restapi.header",
   "type": "enum",
   "name": "DescriptiveStatistic",
-  "doc": "Set of available statical value",
+  "doc": "Statical values",
   "symbols": [
     "AVERAGE" ,
     "COUNT" ,
@@ -13,6 +13,7 @@
     "INTERQUARTILE_RANGE" ,
     "LOWER_QUARTILE" ,
     "UPPER_QUARTILE",
-    "QUARTILES"
+    "QUARTILES",
+    "RECEIVED_MESSAGES"
     ]
 }
diff --git a/restapi/header/effective_time_frame.avsc b/restapi/header/effective_time_frame.avsc
index 9a23ce8a..ec139cb2 100644
--- a/restapi/header/effective_time_frame.avsc
+++ b/restapi/header/effective_time_frame.avsc
@@ -2,7 +2,7 @@
   "namespace": "org.radarcns.avro.restapi.header",
   "type": "record",
   "name": "EffectiveTimeFrame",
-  "doc": "Time window",
+  "doc": "Provide the first and the last timestamp contained in the dataset",
   "fields": [
     {"name": "startDateTime", "type": "string", "doc": "It is a point in time (ISO8601) with UTC timezone."},
     {"name": "endDateTime", "type": "string", "doc": "It is a point in time (ISO8601) with UTC timezone."}
diff --git a/restapi/header/header.avsc b/restapi/header/header.avsc
index 4e130905..06bf7908 100644
--- a/restapi/header/header.avsc
+++ b/restapi/header/header.avsc
@@ -4,8 +4,13 @@
   "name": "Header",
   "doc": "Metadata for Dataset. It is a summary explaining what kind of information are stored in the Dataset.",
   "fields": [
-    {"name": "descriptiveStatistic", "type": "DescriptiveStatistic" },
-    {"name": "unit", "type": "org.radarcns.avro.restapi.sensor.Unit"},
-    {"name": "effectiveTimeFrame", "type": "EffectiveTimeFrame" }
+    {"name": "subjectId", "type": "string", "doc": "Subject identifier"},
+    {"name": "sourceId", "type": "string", "doc": "Source identifier"},
+    {"name": "source", "type": "org.radarcns.avro.restapi.source.SourceType", "doc": "Source type"},
+    {"name": "sensor", "type": "org.radarcns.avro.restapi.sensor.SensorType", "doc": "Sensor that has generated data"},
+    {"name": "descriptiveStatistic", "type": "DescriptiveStatistic", "doc": "Statical value expressed by samples" },
+    {"name": "unit", "type": "org.radarcns.avro.restapi.sensor.Unit", "doc": "Measurement unit with which samples are measured" },
+    {"name": "timeFrame", "type": "TimeFrame", "doc": "Time interval between two consecutive samples" },
+    {"name": "effectiveTimeFrame", "type": "EffectiveTimeFrame", "doc": "Timestamps of the first and the last samples contained in the dataset" }
   ]
 }
diff --git a/restapi/header/time_frame.avsc b/restapi/header/time_frame.avsc
new file mode 100644
index 00000000..9a5e5feb
--- /dev/null
+++ b/restapi/header/time_frame.avsc
@@ -0,0 +1,15 @@
+{
+  "namespace": "org.radarcns.avro.restapi.header",
+  "type": "enum",
+  "name": "TimeFrame",
+  "doc": "Interval between two consecutive samples",
+  "symbols": [
+    "TEN_SECOND" ,
+    "THIRTY_SECOND" ,
+    "ONE_MIN" ,
+    "TEN_MIN" ,
+    "ONE_HOUR" ,
+    "ONE_DAY" ,
+    "ONE_WEEK"
+    ]
+}
diff --git a/restapi/message.avsc b/restapi/message.avsc
index f0c07ea0..3e48342c 100644
--- a/restapi/message.avsc
+++ b/restapi/message.avsc
@@ -2,7 +2,7 @@
   "namespace": "org.radarcns.avro.restapi.avro",
   "type": "record",
   "name": "Message",
-  "doc": "Message to describe HTTP Response",
+  "doc": "Message to provide information to the end user in case a function does not provide the expected result",
   "fields": [
     {"name": "message", "type": "string"}
   ]
diff --git a/restapi/sensor/acceleration.avsc b/restapi/sensor/acceleration.avsc
deleted file mode 100644
index 1c40294a..00000000
--- a/restapi/sensor/acceleration.avsc
+++ /dev/null
@@ -1,11 +0,0 @@
-{
-  "namespace": "org.radarcns.avro.restapi.sensor",
-  "type": "record",
-  "name": "Acceleration",
-  "doc": "Acceleration item for a dataset with gravitational constant g as unit.",
-  "fields": [
-    {"name": "x", "type": [ "double" , "org.radarcns.avro.restapi.dataset.Quartiles" ]},
-    {"name": "y", "type": [ "double" , "org.radarcns.avro.restapi.dataset.Quartiles" ]},
-    {"name": "z", "type": [ "double" , "org.radarcns.avro.restapi.dataset.Quartiles" ]}
-  ]
-}
diff --git a/restapi/sensor/battery.avsc b/restapi/sensor/battery.avsc
deleted file mode 100644
index a4b22359..00000000
--- a/restapi/sensor/battery.avsc
+++ /dev/null
@@ -1,9 +0,0 @@
-{
-  "namespace": "org.radarcns.avro.restapi.sensor",
-  "type": "record",
-  "name": "Battery",
-  "doc": "The battery level resulting from the data aggregation. It is a double value between 0 and 1",
-  "fields": [
-    {"name": "value", "type": [ "double" , "org.radarcns.avro.restapi.dataset.Quartiles" ]}
-  ]
-}
diff --git a/restapi/sensor/blood_volume_pulse.avsc b/restapi/sensor/blood_volume_pulse.avsc
deleted file mode 100644
index 276617ee..00000000
--- a/restapi/sensor/blood_volume_pulse.avsc
+++ /dev/null
@@ -1,9 +0,0 @@
-{
-  "namespace": "org.radarcns.avro.restapi.sensor",
-  "type": "record",
-  "name": "BloodVolumePulse",
-  "doc": "Data from photoplethysmograph expressed in light absorption (nW)",
-  "fields": [
-    {"name": "value", "type": [ "double" , "org.radarcns.avro.restapi.dataset.Quartiles" ]}
-  ]
-}
diff --git a/restapi/sensor/data_type.avsc b/restapi/sensor/data_type.avsc
index 67db33b9..d41c74d1 100644
--- a/restapi/sensor/data_type.avsc
+++ b/restapi/sensor/data_type.avsc
@@ -2,7 +2,7 @@
   "namespace": "org.radarcns.avro.restapi.sensor",
   "type": "enum",
   "name": "DataType",
-  "doc": "States if the value is provided directly by a sensor or it is computed. Any value different from RAW states who computes the value.",
+  "doc": "States if a sample is recorded directly by a sensor or it is computed. Any value different from RAW states who computes the value.",
   "symbols": [
     "RAW" ,
     "VENDOR",
diff --git a/restapi/sensor/electrodermal_activity.avsc b/restapi/sensor/electrodermal_activity.avsc
deleted file mode 100644
index fb73431b..00000000
--- a/restapi/sensor/electrodermal_activity.avsc
+++ /dev/null
@@ -1,9 +0,0 @@
-{
-  "namespace": "org.radarcns.avro.restapi.sensor",
-  "type": "record",
-  "name": "ElectroDermalActivity",
-  "doc": "Aggregated data representing electrodermal activity expressed as microsiemens (µS)",
-  "fields": [
-    {"name": "value", "type": [ "double" , "org.radarcns.avro.restapi.dataset.Quartiles" ]}
-  ]
-}
diff --git a/restapi/sensor/heart_rate.avsc b/restapi/sensor/heart_rate.avsc
deleted file mode 100644
index 23ce4821..00000000
--- a/restapi/sensor/heart_rate.avsc
+++ /dev/null
@@ -1,9 +0,0 @@
-{
-  "namespace": "org.radarcns.avro.restapi.sensor",
-  "type": "record",
-  "name": "HeartRate",
-  "doc": "Heart Rate resulting from data aggregation. It is computed as (60 / ibi)",
-  "fields": [
-    {"name": "value", "type": [ "double" , "org.radarcns.avro.restapi.dataset.Quartiles" ]}
-  ]
-}
diff --git a/restapi/sensor/inter_beat_interval.avsc b/restapi/sensor/inter_beat_interval.avsc
deleted file mode 100644
index fe4fe615..00000000
--- a/restapi/sensor/inter_beat_interval.avsc
+++ /dev/null
@@ -1,9 +0,0 @@
-{
-  "namespace": "org.radarcns.avro.restapi.sensor",
-  "type": "record",
-  "name": "InterBeatInterval",
-  "doc": "Time between individuals heart beats",
-  "fields": [
-    {"name": "value", "type": [ "double" , "org.radarcns.avro.restapi.dataset.Quartiles" ]}
-  ]
-}
diff --git a/restapi/sensor/sensor_type.avsc b/restapi/sensor/sensor_type.avsc
index 48d6e3df..83945dd0 100644
--- a/restapi/sensor/sensor_type.avsc
+++ b/restapi/sensor/sensor_type.avsc
@@ -2,7 +2,7 @@
   "namespace": "org.radarcns.avro.restapi.sensor",
   "type": "enum",
   "name": "SensorType",
-  "doc": "Set of sensor type",
+  "doc": "Sensor types",
   "symbols": [
     "ACCELEROMETER" ,
     "BATTERY",
diff --git a/restapi/sensor/temperature.avsc b/restapi/sensor/temperature.avsc
deleted file mode 100644
index 5852e4bf..00000000
--- a/restapi/sensor/temperature.avsc
+++ /dev/null
@@ -1,9 +0,0 @@
-{
-  "namespace": "org.radarcns.avro.restapi.sensor",
-  "type": "record",
-  "name": "Temperature",
-  "doc": "Temperature value expressed in Celsius (°C) scale",
-  "fields": [
-    {"name": "value", "type": [ "double" , "org.radarcns.avro.restapi.dataset.Quartiles" ]}
-  ]
-}
diff --git a/restapi/sensor/unit.avsc b/restapi/sensor/unit.avsc
index 239b088e..1f0a7709 100644
--- a/restapi/sensor/unit.avsc
+++ b/restapi/sensor/unit.avsc
@@ -2,7 +2,7 @@
   "namespace": "org.radarcns.avro.restapi.sensor",
   "type": "enum",
   "name": "Unit",
-  "doc": "Set of measurement units",
+  "doc": "Measurement units",
   "symbols": [
     "BEATS_PER_MIN" ,
     "CELSIUS",
diff --git a/restapi/source/source.avsc b/restapi/source/source.avsc
index deb2e67b..b1ea6c03 100644
--- a/restapi/source/source.avsc
+++ b/restapi/source/source.avsc
@@ -4,8 +4,8 @@
   "name": "Source",
   "doc": "Source details",
   "fields": [
-    {"name": "id", "type": "string", "doc": "Source id"},
-    {"name": "type", "type": "SourceType", "doc": "Source name"},
-    {"name": "summary", "type": ["null", "SourceSummary"], "default": null, "doc": "Source details"}
+    {"name": "id", "type": "string", "doc": "Source identifier" },
+    {"name": "type", "type": "SourceType", "doc": "Source name" },
+    {"name": "summary", "type": ["null", "SourceSummary"], "default": null, "doc": "Source details" }
   ]
 }
diff --git a/restapi/subject/cohort.avsc b/restapi/subject/cohort.avsc
new file mode 100644
index 00000000..ee6b39a6
--- /dev/null
+++ b/restapi/subject/cohort.avsc
@@ -0,0 +1,10 @@
+{
+  "namespace": "org.radarcns.avro.restapi.subject",
+  "type": "record",
+  "name": "Cohort",
+  "doc": "Cohort definition",
+  "fields": [
+    {"name": "studyId", "type": "int", "doc": "ID related to the study"},
+    {"name": "subjects", "type": {"type": "array", "items": "Subject" }, "doc": "List of Subject involved in the study"}
+  ]
+}
diff --git a/restapi/subject/subject.avsc b/restapi/subject/subject.avsc
new file mode 100644
index 00000000..6cc7c283
--- /dev/null
+++ b/restapi/subject/subject.avsc
@@ -0,0 +1,12 @@
+{
+  "namespace": "org.radarcns.avro.restapi.subject",
+  "type": "record",
+  "name": "Subject",
+  "doc": "Subject definition",
+  "fields": [
+    {"name": "subjectId", "type": "string", "doc": "Subject identifier"},
+    {"name": "active", "type": "boolean", "doc": "True if the subject is engaged, false otherwise. False means the subject is no longer monitored" },
+    {"name": "effectiveTimeFrame", "type": "org.radarcns.avro.restapi.header.EffectiveTimeFrame", "doc": "Timestamps of the first and the last samples received by the subject" },
+    {"name": "sources", "type": {"type": "array", "items": "org.radarcns.avro.restapi.source.Source" }, "doc": "List of sources used by the subject"}
+  ]
+}
diff --git a/restapi/user/cohort.avsc b/restapi/user/cohort.avsc
deleted file mode 100644
index 5e44c7fc..00000000
--- a/restapi/user/cohort.avsc
+++ /dev/null
@@ -1,10 +0,0 @@
-{
-  "namespace": "org.radarcns.avro.restapi.user",
-  "type": "record",
-  "name": "Cohort",
-  "doc": "Cohort definition",
-  "fields": [
-    {"name": "studyId", "type": "int", "doc": "ID related to the study"},
-    {"name": "patients", "type": {"type": "array", "items": "Patient" }, "doc": "List of patients involved in the study"}
-  ]
-}
diff --git a/restapi/user/patient.avsc b/restapi/user/patient.avsc
deleted file mode 100644
index c575110a..00000000
--- a/restapi/user/patient.avsc
+++ /dev/null
@@ -1,10 +0,0 @@
-{
-  "namespace": "org.radarcns.avro.restapi.user",
-  "type": "record",
-  "name": "Patient",
-  "doc": "Patient definition",
-  "fields": [
-    {"name": "userId", "type": "string", "doc": "User identifier"},
-    {"name": "sources", "type": {"type": "array", "items": "org.radarcns.avro.restapi.source.Source" }, "doc": "List of all sources used by the Patient"}
-  ]
-}